Genetics and Reproductive Technologies [addendum] | Research & Encyclopedia Articles

Philosophical scholarship on genetics and reproductive technologies typically follows the development of these scientific fields closely, providing critical analysis of the major assumptions and implications of their emerging claims, often in advance of their realization. This addendum reviews three discussions that have become particularly prominent in the literature since Ruth Macklin's original entry appeared in 1996: debates over the design and interpretation of human genetic variation research, the prospect of human reproductive cloning, and the potential limits of human genetic modification.

The principal outcome of the Human Genome Project was a set of research tools for human genetic variation research. With improved genomic maps and DNA sequencing technologies, geneticists have been able to launch a new generation of projects comparing human genomes to better understand our similarities, differences, and patterns of relationship at the molecular level. These comparisons are critical to the development of successful medical applications of genomic research, as well as to the interests of anthropologists and paleontologists interested in the evolution, differentiation, and global migrations of our species (Risch et. al. 2002). On the other hand, these comparisons also raise two sets of important philosophical issues:

First, how should scientists define and identify the relevant comparison groups within our species? The initial attempt to use genomic tools in a large scale study of human variation, the so-called Human Genome Diversity Project, followed the accepted practice of physical anthropologists and epidemiologists of describing its target groups in ethnic, linguistic, and geographical terms, and was called to task by both biologists and social scientists for using socially constructed categories that would obfuscate rather than illuminate underlying patterns of gene flow within our species (Gannet 2001, Reardon 2005). Rather than reifying various human political histories by looking for "ethnic-affiliation markers" in human DNA, some suggested a random global sampling strategy blinded to social identifiers (National Research Council 1998). The U.S. National Institutes of Health followed this approach in developing a major genetic variation research resource—a databank of known single nucleotide variants in human DNA—and was in turn called to task by public health and pharmacogenomic researchers for omitting "phenotypic data" about the distribution of the DNA variants across different populations (Altshuler and Clark 2005).

As a result, the subsequent international effort to a variation-measuring "haplotype map" of the human genome intentionally collected samples from groups defined by their "continents of origin" (International Hapmap Consortium 2003). Critics charge that this strategy returns population genomics to a set of outmoded racial categories that human scientists of all stripes have repudiated as biomedically meaningless and socially pernicious (Duster 2005). Claims that, nevertheless, research framed in this way has identified patterns of genetic variation that cluster along racial lines, and that these variations may be the key to "population specific" public health interventions or even "race-based medicine," have only lent fuel to this conceptual debate.

The second issue follows from the first. Assuming that, for the foreseeable future, the definition of comparison groups in population genomics will be informed by socially constructed criteria at some level of resolution (either familial, tribal, ethnic, racial, or regional), how should the interests of group members be protected? Outside of groups with clear political sovereignty, like Native American nations, most targets of genetic analysis have ambiguous moral standing. Is it ethically important for scientists to attempt to discuss their plans with groups at the collective level before recruiting individual group members into genetic variation studies? Some argue strongly that a principle of "respect for community" needs to supplement our traditionally individualistic principles of research ethics in these contexts, if only because individuals gain so much of their identity through their community memberships and their genetic lineages (Weijer 1999). Others argue that, at least for genetic studies, extensive efforts at community engagement are disingenuous and guaranteed to fail, given the mismatch between genetic populations and the politically defined communities available for consultation (Juengst 1998).

Philosophical questions about the nature of human identity have been raised from quite another angle, meanwhile, by the successful cloning of a sheep in 1997 (McGee 2000). In that case, the nucleus of a mammary gland cell from an adult ewe was transplanted into an enucleated egg, and, after 280 attempts, coaxed into developing into a genomic twin of the gland cell's donor. If the technique that produced Dolly, the ewe, could be used effectively with humans, it would open up the prospect of adding reproductive cloning to the repertoire of techniques available to those seeking to procreative assistance. This prospect has prompted questions about the personal identity and moral status of the resulting "delayed twin," but these seem easily answered by our experience with natural twins who also have identical genomes: Clearly, the cloned individual would be a distinct person with full moral standing, due full protection against exploitation or abuse by his or her progenitors.

However, anticipating parental expectations for cloned offspring raises more difficult questions. How similar might the cloned offspring be to the progenitor, and what impact should the foreknowledge (or assumption) of such similarities have on the rearing of the offspring? Should progenitors of clones assume special responsibilities to anticipate the health and behavioral challenges their delayed twins may face, or do they, instead, acquire unusual obligations to refrain as much as possible from prejudicing the life experience of their offspring? These questions are animating new work on the nature and ethics of parenting, procreative liberty, and the limits of genetic determinism. They have also given new energy to "natural law" arguments against reproductive technologies in general, by providing a case in which the slippery technological slope seems to lead us to a form of reproduction—asexual reproduction—that contradicts an element of human nature that has been fundamental to our species' identity to date (Lauritzen 2001).

Behind all of these concerns looms a follow-up question that links this discussion to back to the role of genetic lineage in human identity. Given the psychological complexities of cloning and their potential impact on the offspring, is the value of sheer genetic continuity important enough to ever warrant the inclusion of this option on the menus of fertility medicine? Some argue that prospective parents who feel the need for genetic connections with their offspring simply mistakenly essentialistic, and should be re-educated accordingly (Post 1997). Others, however, suggest that the interest in extending the limits of procreative liberty to defend technologies like cloning reflects something important about the role of lineage in human identity which philosophy has yet to fully unravel (Roberts 1995).

The philosophical status of intergenerational genetic connections also lies at the heart of a new generation of attempts to define the appropriate limits of human genetic modification. The provisional boundaries of such a practice were established in the 1980s to provide a window for human gene therapy research. On one axis, a line was drawn between using genetic interventions to treat disease, and using it to attempt to "enhance" human traits to achieve nonmedical goals. On the other genetic interventions that only affected somatic cells were distinguished from those that might lead to intergenerational transmission of modifications, through the "germ-line." Both distinctions have come under recent philosophical critique. The line between treatment and enhancement appears difficult to maintain as a conceptual matter and its moral implications diverge significantly between its personal, parental, professional and public policy applications (Parens 1998). Meanwhile, it begins to appear that the price to pay for successful somatic cell gene therapy will be the development of tools for safe and effective germ-line interventions, and in that light the arguments in favor of abandoning that boundary in the service of medicine are gaining strength (Chapman and Frankel 2003).

Animating these debates is another argument over the importance of our genetic inheritance. Those who strive to preserve the "common genetic heritage of humankind" and protect the rights of future generations to "inherit an untampered genome" argue that our genetic inheritance forms the limits of our "species integrity", the violation of which risks literally de-humanizing ourselves and our offspring (Annas, Andrews, Isasi 2002; Fukyama 2002). On this view, the contours of human nature, and thus the foundations of human moral status, are defined by the pool of genes—and their variants—that humans have collected over the course of our evolution, and any manipulation of that legacy risks distorting or corrupting the human identity of our offspring.

This view is difficult to reconcile with what population genetics, developmental biology and gene transfer research itself teach us about the fluidity of the human genome and its relatively remote role in the human traits we prize most (Robert and Baylis 2003, DeGrazia 2005). Like the interest in race-based genomic medicine and concerns about the moral status of clones, it accepts a level of genetic essentialism that seems more indebted to Aristotle than to James Watson and Francis Crick. Nevertheless, all these views enjoy wide acceptance in both academic and public circles, which is intriguing. Perhaps this convergence signals the next challenge that genetics offers philosophy: to help clarify the role of genetic histories—the genes we inherit, the lineages we belong to, the peoples we spring from—in our identities as human beings and our experience of the human condition. If philosophical anthropology examines what it means to be a human individual, what genetics seems to call for now is a philosophical genealogy: the study of what it means to be a human descendant (Juengst 2004).

Aristotle; Distant Peoples and Future Generations; Human Genome Project; Medical Ethics; Natural Law.

Altshuler, David, and Angus Clark. "Harvesting Medical Information from the Human Family Tree." Science 307 (2005): 1,052–1,053.

Annas, George, Lori Andrews, and Rosario Isasi. "Protecting the Endangered Human: Toward an International Treaty Prohibiting Cloning and Inheritable Alterations." American Journal of Law and Medicine 28 (2002): 151–178.

Chapman, Audrey., and Mark Frankel, eds. Designing Our Descendants: The Promises and Perils of Genetic Modifications. Baltimore, MD: Johns Hopkins University Press, 2003.

DeGrazia, David. "Enhancement Technologies and Human Identity." Journal of Medicine and Philosophy 30 (2005): 261–285.

Duster, Troy. "Race and Reification in Science." Science 307 (2005): 1,050–1,051.

Fukuyama, Francis. Our Posthuman Future: Consequences of the Biotechnology Revolution. New York: Farrar, Straus and Giroux, 2002.

Gannett, Lori. "Racism and Human Genome Diversity Research: The Ethical Limits of 'Population Thinking.'" Philosophy of Science 68 (2001): S479–S492.

International Hapmap Consortium. "The International Hapmap Project." Nature 426 (2003): 789–795.

Juengst, Eric. "FACE Facts: Why Human Genetics Will Always Provoke Bioethics." Journal of Law, Medicine and Ethics 32 (2004): 252-267.

Juengst, Eric. "Groups As Gatekeepers to Genomic Research: Conceptually Confusing, Morally Hazardous and Practically Useless." Kennedy Institute of Ethics Journal 8 (1998): 183–200.

Lauritzen, P. Cloning and the Future of Human Embryo Research. New York: Oxford University Press, 2001.

McGee, Glenn, and Arthur Caplan, eds. The Human Cloning Debate. Berkeley, CA: Berkeley Hills Books, 2000.

National Research Council. Assessing Human Genetic Diversity. Washington, DC: National Academy Press, 1998.

Parens, E., ed. Enhancing Human Traits: Ethical and Social Implications. Washington, DC: Georgetown University Press, 1998.

Post, S. "Adoption Theologically Considered." Journal of Religious Ethics 25 (1997): 149–167.

Reardon, J. Race to the Finish: Identity and Governance in an Age of Genomics. Princeton, NJ: Princeton University Press, 2005.

Risch, N., E. Burchard, E. Ziv, and H. Tang. "Categorization of Humans in Biomedical Research: Genes, Race, and Disease." Genome Biology 3 (7) (2002): 2007.1–2007.12.

Robert, J., and M. Baylis. "Crossing Species Boundaries." American Journal of Bioethics 3 (2003): 1–14.

Roberts, D. "The Genetic Tie." University of Chicago Law Review 62 (1995): 209–273.

Weijer, C. "Protecting Communities in Research: Philosophical and Pragmatic Challenges." Cambridge Quarterly of Health Care Ethics 8 (1999): 501–513.

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